Geoscience Laser Altimeter System (GLAS) Data Products from the Ice, Cloud, and land Elevation Satellite (ICESat) Mission

The Geoscience Laser Altimeter System (GLAS) is the sole instrument being developed to fly on the Ice, Cloud, and land Elevation Satellite (ICESat). The ICESat mission is an integral part of the NASA Earth Science Enterprise (ESE). The ICESat satellite will have a near circular and near polar orbit with an altitude of approximately 600 km and coverage to 86 degrees latitude. The projected launch date for the GLAS instrument on the ICESat satellite is June 1, 2002. The ICESat mission has two sets of objectives. The primary objectives utilize altimetry to study the cryosphere. These goals are to provide accurate, high resolution elevation measurements of the Greenland and Antarctic ice sheets. Time-series of elevation changes will enable determination of the present-day mass balance of the ice sheets and estimation of present and future contributions of the ice sheets to global sea level rise. These data will also increase our understanding of the way that changes in the ice sheets affect changes in polar climate, such as precipitation, temperature, and cloudiness. The secondary objectives utilize Light Detection and Ranging [LIDAR] to study the atmosphere, and altimetry to study land and oceans. These goals are to measure cloud heights and the vertical structure of clouds and aerosols in the atmosphere, land topography and vegetation canopy heights, sea ice roughness and thickness, ocean surface elevations, and surface reflectivity. The ICESat Science Investigator-led Processing System (I-SIPS), at Goddard Space Flight Center (GSFC), will produce level 1A, 1B, 2 and 3 data products. The National Snow and Ice Data Center (NSIDC) will archive level 0 data shortly after ICESat launches, and will archive, distribute, and support all the higher level data products as they become available.